Highly syndiotactic polystyrene (sPS) was achieved for the first time by Idemitsu Kosan Corporation in Japan through catalytic polymerization by using a titaniummetallocene catalyst in 1986. The highly syndiotactic polystyrene has industrially become a highly attractive material due to properties such as a high melting point, a high crystallinity, a high elastic modulus, a low dielectric constant, a low loss factor, a good heat resistance, a good solvent resistance, or the like.
However, the highly syndiotactic polystyrene has a relatively large brittleness and has a critical disadvantage of lacking polar groups in the polymer when used as a material alone, which limits the application field of the highly syndiotactic polystyrene. Therefore, there are always problems to be solved by a large number of scientists and technologists to improve the brittleness of the highly syndiotactic polystyrene, to improve the polarity thereof, and to synthesize functionalized highly syndiotactic polystyrene.
However, polystyrene may be caused to be degraded in the process of modifying polystyrene. A functionalized group may be directly introduced to highly syndiotactic polystyrene by subjecting a functionalized styrene to a highly syndiotactic homopolymerization and then to a highly syndiotactic copolymerization with styrene, such that the problems of polymer degradation or the like which are caused by post-functionalization of the highly syndiotactic polystyrene are avoided. However, styrene containing a functionalized group will easily lose polymerization activity after coordinating a catalyst, and thus the homopolymerization and the copolymerization with styrene of functionalized styrene are also very difficult. In 1990, Kazuo Soga et al., studied the copolymerization of styrene with p-chlorostyrene, m-chlorostyrene, or p-bromostyrene using a Ziegler-Natta catalyst, and the results indicated that the copolymer obtained had a random structure. Later, the researching team of Jungahn Kim used a functionalized styrene protected by a large sterically-hindered group, which was 4-tert-butyldimethylsiloxy styrene, to perform copolymerization with styrene, but the copolymer obtained had a relatively low molecular weight. In 2002, professor T. C. Chung synthesized a copolymer of p-borane functionalized styrene and styrene using a mono-titanocene catalyst, wherein the insertion rate of the functionalized monomers was at most 32.2%.